/*
   * adm1029.c - Part of lm_sensors, Linux kernel modules for hardware monitoring
   *

   * Copyright (C) 2006 Corentin LABBE <clabbe.montjoie@gmail.com>

   *

   * Based on LM83 Driver by Jean Delvare <jdelvare@suse.de>

   *
   * Give only processor, motherboard temperatures and fan tachs
   * Very rare chip please let me know if you use it
   *
   * http://www.analog.com/UploadedFiles/Data_Sheets/ADM1029.pdf
   *
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation version 2 of the License
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
   */
  
  #include <linux/module.h>
  #include <linux/init.h>
  #include <linux/slab.h>
  #include <linux/jiffies.h>
  #include <linux/i2c.h>
  #include <linux/hwmon-sysfs.h>
  #include <linux/hwmon.h>
  #include <linux/err.h>
  #include <linux/mutex.h>
  
  /*
   * Addresses to scan
   */

  static const unsigned short normal_i2c[] = { 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d,
  						0x2e, 0x2f, I2C_CLIENT_END

  };
  
  /*

   * The ADM1029 registers
   * Manufacturer ID is 0x41 for Analog Devices
   */
  
  #define ADM1029_REG_MAN_ID			0x0D
  #define ADM1029_REG_CHIP_ID			0x0E
  #define ADM1029_REG_CONFIG			0x01
  #define ADM1029_REG_NB_FAN_SUPPORT		0x02
  
  #define ADM1029_REG_TEMP_DEVICES_INSTALLED	0x06
  
  #define ADM1029_REG_LOCAL_TEMP			0xA0
  #define ADM1029_REG_REMOTE1_TEMP		0xA1
  #define ADM1029_REG_REMOTE2_TEMP		0xA2
  
  #define ADM1029_REG_LOCAL_TEMP_HIGH		0x90
  #define ADM1029_REG_REMOTE1_TEMP_HIGH		0x91
  #define ADM1029_REG_REMOTE2_TEMP_HIGH		0x92
  
  #define ADM1029_REG_LOCAL_TEMP_LOW		0x98
  #define ADM1029_REG_REMOTE1_TEMP_LOW		0x99
  #define ADM1029_REG_REMOTE2_TEMP_LOW		0x9A
  
  #define ADM1029_REG_FAN1			0x70
  #define ADM1029_REG_FAN2			0x71
  
  #define ADM1029_REG_FAN1_MIN			0x78
  #define ADM1029_REG_FAN2_MIN			0x79
  
  #define ADM1029_REG_FAN1_CONFIG			0x68
  #define ADM1029_REG_FAN2_CONFIG			0x69
  
  #define TEMP_FROM_REG(val)	((val) * 1000)

  #define DIV_FROM_REG(val)	(1 << (((val) >> 6) - 1))

  
  /* Registers to be checked by adm1029_update_device() */
  static const u8 ADM1029_REG_TEMP[] = {
  	ADM1029_REG_LOCAL_TEMP,
  	ADM1029_REG_REMOTE1_TEMP,
  	ADM1029_REG_REMOTE2_TEMP,
  	ADM1029_REG_LOCAL_TEMP_HIGH,
  	ADM1029_REG_REMOTE1_TEMP_HIGH,
  	ADM1029_REG_REMOTE2_TEMP_HIGH,
  	ADM1029_REG_LOCAL_TEMP_LOW,
  	ADM1029_REG_REMOTE1_TEMP_LOW,
  	ADM1029_REG_REMOTE2_TEMP_LOW,
  };
  
  static const u8 ADM1029_REG_FAN[] = {
  	ADM1029_REG_FAN1,
  	ADM1029_REG_FAN2,
  	ADM1029_REG_FAN1_MIN,
  	ADM1029_REG_FAN2_MIN,
  };
  
  static const u8 ADM1029_REG_FAN_DIV[] = {
  	ADM1029_REG_FAN1_CONFIG,
  	ADM1029_REG_FAN2_CONFIG,
  };
  
  /*

   * Client data (each client gets its own)
   */
  
  struct adm1029_data {

  	struct i2c_client *client;

  	struct mutex update_lock;
  	char valid;		/* zero until following fields are valid */
  	unsigned long last_updated;	/* in jiffies */
  
  	/* registers values, signed for temperature, unsigned for other stuff */
  	s8 temp[ARRAY_SIZE(ADM1029_REG_TEMP)];
  	u8 fan[ARRAY_SIZE(ADM1029_REG_FAN)];
  	u8 fan_div[ARRAY_SIZE(ADM1029_REG_FAN_DIV)];
  };
  
  /*

   * function that update the status of the chips (temperature for example)
   */
  static struct adm1029_data *adm1029_update_device(struct device *dev)
  {

  	struct adm1029_data *data = dev_get_drvdata(dev);
  	struct i2c_client *client = data->client;

  
  	mutex_lock(&data->update_lock);
  	/*
  	 * Use the "cache" Luke, don't recheck values
  	 * if there are already checked not a long time later
  	 */
  	if (time_after(jiffies, data->last_updated + HZ * 2)
  	 || !data->valid) {
  		int nr;
  
  		dev_dbg(&client->dev, "Updating adm1029 data
  ");
  
  		for (nr = 0; nr < ARRAY_SIZE(ADM1029_REG_TEMP); nr++) {
  			data->temp[nr] =
  			    i2c_smbus_read_byte_data(client,
  						     ADM1029_REG_TEMP[nr]);
  		}
  		for (nr = 0; nr < ARRAY_SIZE(ADM1029_REG_FAN); nr++) {
  			data->fan[nr] =
  			    i2c_smbus_read_byte_data(client,
  						     ADM1029_REG_FAN[nr]);
  		}
  		for (nr = 0; nr < ARRAY_SIZE(ADM1029_REG_FAN_DIV); nr++) {
  			data->fan_div[nr] =
  			    i2c_smbus_read_byte_data(client,
  						     ADM1029_REG_FAN_DIV[nr]);
  		}
  
  		data->last_updated = jiffies;
  		data->valid = 1;
  	}
  
  	mutex_unlock(&data->update_lock);
  
  	return data;
  }
  
  /*

   * Sysfs stuff
   */
  
  static ssize_t
  show_temp(struct device *dev, struct device_attribute *devattr, char *buf)
  {
  	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
  	struct adm1029_data *data = adm1029_update_device(dev);
  	return sprintf(buf, "%d
  ", TEMP_FROM_REG(data->temp[attr->index]));
  }
  
  static ssize_t
  show_fan(struct device *dev, struct device_attribute *devattr, char *buf)
  {
  	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
  	struct adm1029_data *data = adm1029_update_device(dev);
  	u16 val;

  	if (data->fan[attr->index] == 0
  	    || (data->fan_div[attr->index] & 0xC0) == 0

  	    || data->fan[attr->index] == 255) {
  		return sprintf(buf, "0
  ");
  	}
  
  	val = 1880 * 120 / DIV_FROM_REG(data->fan_div[attr->index])
  	    / data->fan[attr->index];
  	return sprintf(buf, "%d
  ", val);
  }
  
  static ssize_t
  show_fan_div(struct device *dev, struct device_attribute *devattr, char *buf)
  {
  	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
  	struct adm1029_data *data = adm1029_update_device(dev);

  	if ((data->fan_div[attr->index] & 0xC0) == 0)

  		return sprintf(buf, "0
  ");
  	return sprintf(buf, "%d
  ", DIV_FROM_REG(data->fan_div[attr->index]));
  }
  
  static ssize_t set_fan_div(struct device *dev,
  	    struct device_attribute *devattr, const char *buf, size_t count)
  {

  	struct adm1029_data *data = dev_get_drvdata(dev);
  	struct i2c_client *client = data->client;

  	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);

  	u8 reg;

  	long val;
  	int ret = kstrtol(buf, 10, &val);
  	if (ret < 0)
  		return ret;

  
  	mutex_lock(&data->update_lock);
  
  	/*Read actual config */
  	reg = i2c_smbus_read_byte_data(client,
  				       ADM1029_REG_FAN_DIV[attr->index]);
  
  	switch (val) {
  	case 1:
  		val = 1;
  		break;
  	case 2:
  		val = 2;
  		break;
  	case 4:
  		val = 3;
  		break;
  	default:
  		mutex_unlock(&data->update_lock);

  		dev_err(&client->dev,
  			"fan_div value %ld not supported. Choose one of 1, 2 or 4!
  ",
  			val);

  		return -EINVAL;
  	}
  	/* Update the value */
  	reg = (reg & 0x3F) | (val << 6);

  	/* Update the cache */
  	data->fan_div[attr->index] = reg;

  	/* Write value */
  	i2c_smbus_write_byte_data(client,
  				  ADM1029_REG_FAN_DIV[attr->index], reg);
  	mutex_unlock(&data->update_lock);
  
  	return count;
  }
  
  /*

   * Access rights on sysfs. S_IRUGO: Is Readable by User, Group and Others
   *			   S_IWUSR: Is Writable by User.
   */

  static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
  static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp, NULL, 1);
  static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_temp, NULL, 2);
  
  static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO, show_temp, NULL, 3);
  static SENSOR_DEVICE_ATTR(temp2_max, S_IRUGO, show_temp, NULL, 4);
  static SENSOR_DEVICE_ATTR(temp3_max, S_IRUGO, show_temp, NULL, 5);
  
  static SENSOR_DEVICE_ATTR(temp1_min, S_IRUGO, show_temp, NULL, 6);
  static SENSOR_DEVICE_ATTR(temp2_min, S_IRUGO, show_temp, NULL, 7);
  static SENSOR_DEVICE_ATTR(temp3_min, S_IRUGO, show_temp, NULL, 8);
  
  static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, show_fan, NULL, 0);
  static SENSOR_DEVICE_ATTR(fan2_input, S_IRUGO, show_fan, NULL, 1);
  
  static SENSOR_DEVICE_ATTR(fan1_min, S_IRUGO, show_fan, NULL, 2);
  static SENSOR_DEVICE_ATTR(fan2_min, S_IRUGO, show_fan, NULL, 3);
  
  static SENSOR_DEVICE_ATTR(fan1_div, S_IRUGO | S_IWUSR,
  			  show_fan_div, set_fan_div, 0);
  static SENSOR_DEVICE_ATTR(fan2_div, S_IRUGO | S_IWUSR,
  			  show_fan_div, set_fan_div, 1);

  static struct attribute *adm1029_attrs[] = {

  	&sensor_dev_attr_temp1_input.dev_attr.attr,
  	&sensor_dev_attr_temp1_min.dev_attr.attr,
  	&sensor_dev_attr_temp1_max.dev_attr.attr,
  	&sensor_dev_attr_temp2_input.dev_attr.attr,
  	&sensor_dev_attr_temp2_min.dev_attr.attr,
  	&sensor_dev_attr_temp2_max.dev_attr.attr,
  	&sensor_dev_attr_temp3_input.dev_attr.attr,
  	&sensor_dev_attr_temp3_min.dev_attr.attr,
  	&sensor_dev_attr_temp3_max.dev_attr.attr,
  	&sensor_dev_attr_fan1_input.dev_attr.attr,
  	&sensor_dev_attr_fan2_input.dev_attr.attr,
  	&sensor_dev_attr_fan1_min.dev_attr.attr,
  	&sensor_dev_attr_fan2_min.dev_attr.attr,
  	&sensor_dev_attr_fan1_div.dev_attr.attr,
  	&sensor_dev_attr_fan2_div.dev_attr.attr,
  	NULL
  };

  ATTRIBUTE_GROUPS(adm1029);

  
  /*
   * Real code
   */

  /* Return 0 if detection is successful, -ENODEV otherwise */

  static int adm1029_detect(struct i2c_client *client,

  			  struct i2c_board_info *info)

  {

  	struct i2c_adapter *adapter = client->adapter;

  	u8 man_id, chip_id, temp_devices_installed, nb_fan_support;

  	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))

  		return -ENODEV;

  	/*
  	 * ADM1029 doesn't have CHIP ID, check just MAN ID

  	 * For better detection we check also ADM1029_TEMP_DEVICES_INSTALLED,
  	 * ADM1029_REG_NB_FAN_SUPPORT and compare it with possible values
  	 * documented
  	 */

  	man_id = i2c_smbus_read_byte_data(client, ADM1029_REG_MAN_ID);
  	chip_id = i2c_smbus_read_byte_data(client, ADM1029_REG_CHIP_ID);
  	temp_devices_installed = i2c_smbus_read_byte_data(client,

  					ADM1029_REG_TEMP_DEVICES_INSTALLED);

  	nb_fan_support = i2c_smbus_read_byte_data(client,

  						ADM1029_REG_NB_FAN_SUPPORT);

  	/* 0x41 is Analog Devices */
  	if (man_id != 0x41 || (temp_devices_installed & 0xf9) != 0x01
  	    || nb_fan_support != 0x03)
  		return -ENODEV;
  
  	if ((chip_id & 0xF0) != 0x00) {

  		/*
  		 * There are no "official" CHIP ID, so actually
  		 * we use Major/Minor revision for that
  		 */

  		pr_info("Unknown major revision %x, please let us know
  ",
  			chip_id);

  		return -ENODEV;

  	}

  	strlcpy(info->type, "adm1029", I2C_NAME_SIZE);

  	return 0;
  }

  static int adm1029_init_client(struct i2c_client *client)
  {
  	u8 config;
  
  	config = i2c_smbus_read_byte_data(client, ADM1029_REG_CONFIG);
  	if ((config & 0x10) == 0) {
  		i2c_smbus_write_byte_data(client, ADM1029_REG_CONFIG,
  					  config | 0x10);
  	}
  	/* recheck config */
  	config = i2c_smbus_read_byte_data(client, ADM1029_REG_CONFIG);
  	if ((config & 0x10) == 0) {
  		dev_err(&client->dev, "Initialization failed!
  ");
  		return 0;
  	}
  	return 1;
  }

  static int adm1029_probe(struct i2c_client *client,
  			 const struct i2c_device_id *id)
  {

  	struct device *dev = &client->dev;

  	struct adm1029_data *data;

  	struct device *hwmon_dev;

  	data = devm_kzalloc(dev, sizeof(struct adm1029_data), GFP_KERNEL);

  	if (!data)
  		return -ENOMEM;

  	data->client = client;

  	mutex_init(&data->update_lock);

  	/*
  	 * Initialize the ADM1029 chip
  	 * Check config register
  	 */

  	if (adm1029_init_client(client) == 0)
  		return -ENODEV;

  	hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
  							   data,
  							   adm1029_groups);
  	return PTR_ERR_OR_ZERO(hwmon_dev);

  }

  static const struct i2c_device_id adm1029_id[] = {
  	{ "adm1029", 0 },
  	{ }
  };
  MODULE_DEVICE_TABLE(i2c, adm1029_id);

  static struct i2c_driver adm1029_driver = {
  	.class		= I2C_CLASS_HWMON,
  	.driver = {
  		.name = "adm1029",
  	},
  	.probe		= adm1029_probe,

  	.id_table	= adm1029_id,
  	.detect		= adm1029_detect,
  	.address_list	= normal_i2c,
  };

  module_i2c_driver(adm1029_driver);

  MODULE_AUTHOR("Corentin LABBE <clabbe.montjoie@gmail.com>");

  MODULE_DESCRIPTION("adm1029 driver");
  MODULE_LICENSE("GPL v2");